Telephony or telegraphy.



S. G. .BROWN .om www. @any B HH Nw ,0 1 HT P Bm LL EP TP Patented Dec. 24, 1912| s. G. BROWN. IFLEPHONY- 0R TELBGRAPHY.

APPLIOATION FILED DEO. 28, 1908.

Patented Deo. 24, 1912.

2 SHEETS-SHEET 2.

" cording'to Ohins law'.

- UNITED sTATEs PATENT oFFIoE.

SIDNEY GEORGE BROWN, 0F LONDON, ENG-LAND.

TELPHONY OR`TELEGRA1HY.

To all whom t may concern:

Be it known that I, SIDNEY Gannon BROWN, a subject of the King of Great Britain, residing at 4 Great Vinchester street, in the city and county of London, England, have inventedvcertain new and'uset'ul Improvements in or Relating to Telephony or Telegraphy, of which thefollowing is a specification.

This invention relates to systems for the electrical transmission and reception of signals particularly telephonie systems, and `has for its chief object to increase the am.- plitude of the sound waves or signals so as to render the samemore distinct and defined and to enable minute or imperfectsounds or signals to be transmitted andreceived or recorded with greater precision, certainty and clearness than by the methods heretofore practised. y

The present invention is based on the result of investigations in connection with separated contacts or conductors andthe voltage of current necessary for producing sparking across the space between such conductors. Then the distance of separation between the contacts or conductors is very smal or of molecular dimensions, such for instance. that 'comparable with a wave length of sodium light, conduct-ion`takes place, such conduction seeming to vary acvThe invention therefore consists essenv tially in' utilizing the aforesaid conducting space for the purpose of magnifying signals or sound wavesgthe contacts or conductorsbeing arranged'in such a manner that by means ot" an electric current the said conducting space is formed and maintained and adjusted and the requisite degree of conduction between the contacts is insured. f

According to this invention, the aforesaid conduction space is formed by employtwo or more conducting pieces or con'- tacts ot suitable inat'eri l, o'ne of which cont; ts is adapted to b moved by electro- -tic or other snitableforcel so as to land maintain and regulate the molecu- .r distance between. the contactsY against stance of a counteracting force. As c i stance to the current traversing this erede ermined space varies rapidly with any fhtvariation that 'may be brought about Specification of 'Letters Patent.

Application 'lled December 2'8, 1908. vSerial No. 469,651.

Patented Dec. Z4, 1912.

in the distance between the contacts, a very sensitive detector of the minutev relative vmovements which take place between the vuse in telephony.

The sensitiveness of the present method of operation depends upon the smallness of the distance between the contacts and conse quently any metals that oxidi'ze under ordinary atmospheric conditions are likely to affect the sensitiveness owing to the oXid intervening between the contacts. Although the contacts may be composed of any suitable metal they are for the reasons above mentioned preferably composed of any of the non-oxidizable metals, such as thosefbelonging to the platinum group, or of gold. Iridium has been found to give the best results in practice, and, for this reason, is preferred, but silver or steel may be used, although for the .purpose of thepresent invention the latter should possess a highly polished surface; other metals may also be found suitable.v Carbon may be employed' if possessing good conductive or metallic ropelties. If iridium (highly polished be used for the contacts the local battery may have a voltage of approximately half a volt, but if steel be used a local current of about two volts will be required.v Where steel is employed for the contacts, the sensitiveness may be increased by' coating theA same with, or working the contacts under,

oil vor paraiiin. With iridium contacts, however, it is best to Work them dry, the paraiiin having the dieet of reducing the sensitiveness. Carbon contacts would also result in;

a diminution of the sensitivenss.

As a means of producing a variation in the distance between the contacts orof maintaining the conduction spacepitwill be'v understood `that any means suitable for the purpose of the present. invention i may be used." For example I may employ a. coil suspended in a magnetic field, a hea d wire, expansion or contraction of an iron core or the like; infact any meansadapted tb effect the.requisite adjustment of the conducting space by means of the current passing between the contacts'is applicable to the present invention. it may further be stated that any mechanical vibration whatever would space and so'vary the -or embodiments of the invention.

Figure l is a partial sectional elevation lof a telephonie transmitter embodying'the invention; Fig. 2 shows the invention e1nployed in connection with a stethoscope; Fig. 3 shows the invention applied to a telephone relay, the conduction space betweenthe contacts being varied and controlled respectively by electromagnets arranged in the line and local circuits. Fig.

. 4- shows a similar. device in which the line and local electromagnets are superimposed; Fig. 41 shows a. modified form of arrangement of the line connections with the line electromagnet. Fig. 5 is a sectional elevation of a modified form ofrelay; Fie: 6 is a diagrammatic view showing the electricalv connections therefor; Fig. 7 yis a view of a relay, in which the conduction space between the contacts is varied and maintained respectively by a line electromaa'net and a eurrent carrying wire in the local circuit. Fig. 8 shows a telephone relay'l which is sensitive vto vibrations either mechanically or electrically produced. Y

Accordingq to the arrangement of the improved system shown in Fig. l, a aare two 'contacts or conductors, the one f1 being'v carried by a screw b capable of fine adjustment by means of the head brand the other a beine;v mounted upon a dish or diaphragm- .e supported at itsV periphery and capable of vibrating under the action of the sound waves entering the mouthpiece The con tact a is also capable of moving under the influence of an electromagnet f' which is arranged in series with the contacts a a in the local circuit of the battery B; the electromagnet'being energized by the current in the said local circuit, so as to eect the separation of the contacts@ a and thereby form the aforesaid conduction space; the latter being' maintained by the act-ion of the said electromagnet. Any variation in the conduction space or the degree of separation 'of the contacts produced by the variations .'1n the'voice will have spondmg'ly varying the reslstance 1n the the eitl'ect of correlocal circuit, the sound waves being magnified inl the local. circuit and transmitted through the main line to the receiver or telephone T. lt will be seen that the current from the battery B passes by way of the electrodes or contacts@ a through the vibraytory disk or vdiaphragm e into the winding oi the electromagnet f then through the inductance coil IL back to the battery B. Thus by the energization contacts are opened by the .y local current, the said magnet acting to open the contacts until the included resistance of such opening cuts down the local current to prevent furof the electromagnet the ther action of the magnet the latter then.

maintaining the conduction space Upon the local current being switched oit the contracts will become closed owing to the relaxation ot the force which has held them open.

In order to prevent buzzing, as in case of a bell, the vibrations of the adju/@table electrode or contact are regulated by means of the indfucta-nce coil it; the latter having the effect of prevent-ing' currents in the telephone circuit T from ilowinn' into the velectromagnet f the conduction space. 0r the voltage of the which acts slowly to maintain local current may be regulated or reduced in any'suitable manner to suit the particularmetal employed for the cont-acts. A. dashpot device may moreover form part of or be carried by the disk or diaphragm e whereby the aforesaid regulation may be effected. The inductance it may be replaced by a resistance (not shown) arranged in series with theelectromagnet f and serving to counteract any tendency to vibration or to' vary the time period; a capacity arranged across the winding; of the'electromagnet f would have a'like eect.' The condenser z' in the telephone circuit T acts to normally prevent the current in the local circuit from passing in'to the line.

In the arrangement shown in Fig. 2, the vibratory Contact a is superimposed on the nonyibratoryl contact a. The contact a is mounted on the disk e which is carriedlby a hinged frame capable of ineadjustmentby means-of the screw lc which is arranged to work through the stationary frame Z22 and to engage, by its extremity, the aforesaid hinged frame By these means the adjustment-of the contact a is obtained but yin working, when the vibratory contact is subjectedA to movement, as, for instance, in a manner such as described with reference to Fig. l, the local current actu'ates the magnetl f* so as to maintain and regulate the' conduction space. A mouthpiece, as at d, l, may be arrangednn,connection with ,the vibrator-y contact afbutfin` the figure under description, the utilityrofv the invention is exemplified by its connection with a stethoscope Z. It will be seen that the con tacts a a are arranged in the local battery circuit, the battery beingv indicated at B. The inductance 7L` in this circuit, is for preventing currents in the telephone circuit T from flowing into the magnet coil fx which is suspended by the connections fx* from the disk e pertaining to the Contact a, and which 'magnet 'coil is also arranged in the circuit of the battery B. The said magnet coil f* acts Slowly to maintain the con'duction'space. The magnet im is constantly 4energized by the current from the battery m and tends 4to maintain the magnetism of the core m2.

ln order to prevent any Vself vibrator'y movement `of the winding fx, the latter may be provided with a lining of copper or other conducting metal or material. The inductance a in the telephone circuit T. is'for the purpose of tuning. l

Referring -to Fig; 3, the conduction space between the contacts a a is varied and controlled by the line magnet f" and l the local 'magnet fx respectively. The upper 4'contact is 'carried by the arm 0 which may he capable ot tine adjustment bymeans of the' screw o2. The 'current .from the local battery B 'passes to the. upper contact a and from thence "to the lower contact a," the disk or diaphragm e and the electromagnet y fx through the galy'anometer G or other indi-` cating instrument andself-inductfon coil la.y back to the battery B. The electromagnet fo is energized in correspondence-with the v'variations ofthe signals orfsound Vwaves and this variable energization yof the aforesaid .elec-f tromagnet produces corresponding variations in the conduction space between the contacts a a; the resistance to -the passage therewith a condenserz'. 'This arrangement "The transformer t tFig. 3) is shown for retransmitting the signals, theiprimary of the said transformer being shunted across the contacts c, c and having arranged A1n series being general, needs further description.

Figure l shows an arrangementl in which` the line elect-romagnet f and the local elec'- tromagnet f are superimposed.' The ,vibra-` tory contact a is `mounted upon the ,diaf'f phragm the contact d being-,mounted upon. tbefcore a2 ofthe aforesaid electro#i magnets..Y The currentflowsfrom the local battery B to the Contact a, lthen to the contact a,core o, electromagnet winding f, induction coil 7L back to .the battery B. Across the contacts aand a' the receiver r and condenser a'. are shunted as in the previously described arrangements. The `ac' tion of the magnet-fx in this arrangement is to release the upper contact and allow the latter to move away fromfthe lower contact which is inounted on the'core a?. The coil fo carries the currents that vibrate the contact a which is mounted onth'e diaphragm Instead of arranging the line connections 'I with the magnet f in the mannerslaow'n in Iof t e electromagnets f", f

full lines they may be arranged as shown in F1g. 4, a 'condenser being placed in series therein as shown at z". If desired, the mag-` -nets` fof* mayzconstitute one and the same magneti .According to the construction illustrated in Fig. `5, the apparatus comprises an outer metallic casing A having a cover plate a3 carrying the hinged member c for the contact a:- V The cover plate a3 is provided .with an opening a* through which the contact a projects to engage the vibratory contact a carried by the-disk or diaphragm e. Avery sensitive adjustment of the Contact o is obs l l tained by means of the screws 7c and lo.

The-lower contact a is influenced by the electromagnets f and f* which are mounted upon the' support d carrying the depending port-ion or 'permanent magnet d', the latter bein secured to the soft iron cores a a2* magnets fo fx are Athus polarized by the permanent magnet d. A distance piece o5 of X. AThe electronon-magnetic material is placed between th'e coresyo2 a2 and the arms of the depending member-for permanent magnet, and the parts are-secured together by a holte6 and nut A, the partsy carried thereby may be acl--y justed vertically, 'so that the ends of the cores azf lag* maybe arranged lnearer to'or farther away from the disk or diaphragm.

e; the'said partsbeing yretained in the adjusted position by means of the4 jam screw 07. screwing the'support d up or down in the screw threaded vpart (Pof the casing d3. The electrical connections pertaining` yto this'constrru'ction willbe understood from.

theA diagrammatic View thereof shown in.

FigQ. 'In'this ligure, B indicates the local l y battery, /ltfthe'indilctiony coil, t the receiving the condenser .in he latter.

lines and t vthe xetransmitting lines; e' is which shows y.the lamountof current that 'iows' through the conducting space and thus yanometer or othr indicating instrument indicates the normal. resistance between the contacts. When signals or sound waves are being transmitted along the .line t the magnet f is energized and vibrates the lower contact a therebyvaiying the conduction space which is maintained byl the local magnet fx. 'The variations produced in the local circuit will be transmit-ted along the line tvlto thedistant. station. The induction coil 7L, which vmay have an iron core uand be o5 to2@ lhenriesA-induction, is

placed in series with the conduction space adjusting electromagnet fx sogas to give` the electromagn'et a slow period of electrical Vi-v bration. l"lhusithe adjusting lectromagnet is Anot affected' by `the quicl'vibrations pro` duced 4on the circuit by telephone currents flowing in the electromagnets fo', at the same l time the tendency for it to produce/a. vi-

bration on fthe contact is prevented. 1 It iso` one endto a disk or spring strip e", which vee rent-through)the',Wire o has 'theelfecti of expand andlengthen and so .bringzfabout the' .phone .tive to vibrations either mechanically or vable relatively to the contact, a by being will be understood that the electromagnet f acts to open the contacts until the ineluded resistance of such opening cuts down the local current to prevent further action of the magnet, at which point the action of the magnet maintains the conduction space. Instead of arranging-the coils fo fX as shown and described they may constitute one and the same coil.l The coils may be diHerently arranged. Fo'r instance they may be disposed separately on the-saine side or on opposite sides of the disk or arm.

According to Fig. 7 the degree of separation of the contacts is regulated or the conductionl space maintained by means of a wire 0, of metal which is connected 'at may be of steel, carrying the vibratory cori-- tact ai, and at the other end to an arm o p y "inclosing the instrument in a suitable heat land vj-sound proof casing having the adjustcapable of ne adjustment by means of thescrew o2. The frame or supporting part g of the device is preferably of the salinev metal 'or of metal having the same co-eix cient of expansion asjthewire o so as to avoid any ill-effects as the result of -unf equal expansion. The current from the bat-, tery B passes to the contact a thence. to the. contact o and along the stripzcfand the wire o, through the 4inductionA coil-r back tothe batteryf,I v-Thepassage of the cur-` heating the VlatterV andcausing the same to separationof the contacts a o?, and the.v

forming and maintaining ofv the conduction' space vbetweenthem.'` When theteleplionei transmitter (not shown) isspoken into, the ll souiid'waves produceflvariations in the ener, gization of the main ,-linepolarized electrofl magnet f", producing .corresponding variay Y' tions ni the resistance of` the aforesaid lcon-f duction space and thus operating the tele#4 Although'l. have. not shown a galvanom-v eter'or indicating instrument in-connection with each arrangementzherein described it will be readily understood that such or a similar. suitable instrument may form a part of any-equipment for the purpose of my invention.

In lthe' above described examples, theconduction space is adjusted and maintained by means of electromagnets and also by means of an electrically heated wire; it will however be obvious that-the saidspacel may be 4maintained by direct mechanical means, and in Fig. 8 1 have sliownamethod of working in which the'arrangement is sensielectrically produced.

u c are the contacts, whichare insulated finom one anothei.' by the insulation shownl at an, the contact a being rendered adjustioynted at the extremity of the 4iron screw a". The contact a. is carried bythe core of the polarizedl electro-magnet -f which is arranged in the local battery circuit as shown. The contact o isfurther carried y conduction space thus formed is sensitive to vibration which vibration may be caused vby the telephone Icurrent flowing in the magnet winding f,

vWhen constructed forworking as a relay inconnection wit-h telephony, theinstrument is sensitive to variations in tempera ture 'if constructed of materials which eX- i andfwith ,heat-l, This may be overcome by ing means: brought outside or by constructmetal, .whichgis not affected by heat or variations in';temperantre,,0r of metal or metals,

having the same .'.co'etl icient'of expansion.

The sensitivenes of the' instrument when arranged to actas. -a telephone relay y may be increased for any particular tone or rate lof vibrationby making the natural period of .1 -vibration of 'themovable contact or conor iite of movement for rendering they'relay operative.

'f duetor in resonance with any particultr note ...,It will be understood that a switch or equivalent deviceY may be inserted in the "alieiigcuiufor the purpose of economy n working, the switching off of the local iQrrent causing the contacts totouch each other and t-he switching on of the saidcurrnt causing the contacts to open as herevlnbefore described. The contacts` may be o f any ,suitable-conformation but for efficient working the form of the contacts shwn in the accompanying drawings when vconstructed of iridiuir highly polished and having asto the one contact a flat surface and as to the other a `curved or ball termination have been most satisfactory.

The contacts or conductors may be worked in a vacuum or an insert gas with les A a View to preventing chemical changes taking place.

AThe invention is applicable totelephony, as hereinbeyfore described, but itis alsoapplicableto the branch of telegraphy to those pertaining to telephony. What I claim and desireto secure by Letters Patent of the United States is 1. In asyStem for the electric transmissiouand Areception of signals, the combination vof a pair of contacts, 'a source of current in4 circuit therewith, and meansenergized ,byy [the current traversing said conwhich deals with, minute currents, similar noce-14a l tacts, for maintaining a. minute' predetermined conduction `space between' the said contacts. l

3. In a system vfor the electric `transmissionand reception of signals the combination of a pair of contacts, a source of currentfin circuit therewith, means energized by the current traversing said contacts for maintaining a minute conduction space between the said contacts and means for varying the aforesaid conduction space.

4. In a system for the electric transmission and reception of signals, the combination of a plurality 'of contacts, a source of current in circuit therewith, means energized by they current traversing said contacts, for maintaining a minute conduction space between the same and means for Varying the aforesaid' conduction space.

5. In a system for the electric transmission and reception of signals, the combination of a pair of contacts a source of current in circuit therewith, means energized by the current traversing said contacts for maintaining, a minute conduction space between the same and means for varying the aforesaid space in accordance with the variations of the signals.

6. In'a system for the electric transmission and reception of signals, contacts, a source of current in circuit therewith, a local elect-ric circuit containing the contacts, and means, energized bythe current traversingl said contacts, Aadapted to open the said contacts and adjust and maintain a minute conduction space between the contacts.

7. In the electrical transmission' and reception of signals, the combination of contiguous contacts, a source of current in circuit therewith, a telephone circuit, means energized by the current in said telephone circuit, for forming),r and adjusting and maintaining a minute conduction space between thc said contacts and means for vary- -ingr the said conduction space.

8. In the electrical transmission 'and reception of signals, the-combination of two contacts, a magnetic force for forming and maintainingT and adjusting a minute conduction space between the said contacts by adapting the said force to act on one of the contacts and means for producing a counteracting force for varying the conduction space, the electromagnetic force being dependent on the value of thecurrent which passes through the contacts and across the said conduction space.

9. In a system for the electric transmission and reception of signals, the combina,-

tionl of a pair of contacts composed of non-v oxidizable metal, a source of current in circuit therewith, means energized by the current traversing said contacts for forming and adjusting and maintainingr a minute conduction space between the same and` means for varying,r the said conduction space.

10. In the electrical transmission and `re` ception of signals, the combination cfa pair of contacts .whereof one is adapted to be vihrated, asource of current in circuit therewith, and means energized by the current traversing said contacts, for adjusting the vibratory contact so as to form and maintain a minute conduction space between the said contacts. l

1l. In the electrical transmission and reccption of signals, the combination of a pair of contacts, mechanical. means for adjustingl one of the contacts and electrical means for forming' and adjusting' and 'maintaining a minute conduction space between the contracts.

12.111 the electrical transmission and reception ofsignals, a pair of contacts, me-

chanical means for adjusting one of the contacts, and electrical means arranged in a local circuit and adapted to be traversed by the local current so as to 'form and adjust and, maintain a minute conduction spa-ce between the cont-acts, and means adapted to vary the' conduction space between the contacts traversed by the local current.-

13. In the electrical transmission and reception of signals, the combination of a pair of contacts, a source of current in circuit therewith, an electromagnet, a current carryingwire adapted to form and adjust and maintain a minute conduction .space between said contacts, a frame carry-ingr said current carrying wire and means for connecting said wire to one of the`contacts.

14. In the electrical transmission and reception of signals, the combination of a plurality of cont-acts, a source of current in circuit therewith, means energized by the current traversing said contacts, for forming and adjusting and maintaining a minute conduction space between the contacts, means for varying said conduction space to increase the amplitude of the signals, means for transmitting the said signals and means for receiving the same.

l5. In the electrical transmission and reception of signals, the combination of a pair of contacts, means for mechanically adjusting one of the contacts relatively to the other, means for rendering the other contact capable of vibration, a local batt-ery circuit in which the said contacts are included, means energized by the current flowing in said local circuit, for forming and adjusting and Vmaintaining a minute conduction space ,ist

maintaining a minute conduction space be tween the contacts, an electromagnet, inthe line for varying the conduction space and means adapted 'to regulate the period of vibration of the said local electromagnet.

17. In a system 'for the electrical transmission and reception of signals, the combination .of a plurality of contacts working under oil, a source of current in circuit therewith andmeans energized by the current traversing said contacts for maintaining a minute conduction space between the same. v

18. In a system for the electrical transmission and reception of signals, a relay comprising in combination a plurality of contacts, a source of current in circuit there` with, means in circuit with said source of ,current adapted to form and adjust and maintain a conduction space between said contacts, and means for varying the aforesaid space in accordance with the variations of the signals. v l 19. In the electrical transmission and reception of signals, the combination of a vi bratory contact, a non-vibratory Contact in minute conduction space which is formed and maintained by said local means.

20. In the electrical transmission and reception of signals, the combination of a vibratory contact, a spring strip carrying the said vibratory contact, a non-vibratory contact, means for adjusting the said non-vibratory contact relatively to the vibratory contact, and local electrical means adapted f to control the microphonic space between the said contacts and which is formed and maintained by the said local means.

21. In the electrical transmission and reception of signals, the combination 0f a vibratory contact, a rccd for carryingthe said vibratory Contact, a non-vibratory Contact, mechanical means for effecting the adjustment oi' said contacts whereby more or less current is allowed to traverse' the same, and local electrical means for controlling the microphonic space which is formed and maintained by the said local means.

In testimony whereof I aflix my signature in presence of two witnesses.

SIDNEY GEORGE BROWN. Witnesses: i

T. SELBY WARDLn,

WALTER J. SKERTEN. 

